1. Field of the Invention
The present invention relates to a conveying apparatus including a car type conveyor or a slat conveyor and fitted with carriers.
2. Description of Related Art
Conveying apparatus of this type are disclosed in Japanese Unexamined Patent Publication Nos. H7-157039 and H7-172538, for example. Each of these apparatus vertically moves carriers by means of a cam rail extending along a running track, not by means of cylinder units or other actuators, each of which might be fitted to one of the plates.
The conveying apparatus disclosed in Publication No. H7-157039 includes a slat conveyor extending along a running track. The slat conveyor is fitted with elevators at intervals along it. The elevators can move vertically relative to the slat conveyor, and each of them directly supports a carrier. A cam rail is fixed relative to the slat conveyor and lifts the elevators. The cam rail makes it possible to keep the carriers at an elevated position in a limited section of the running track. The strokes of the elevators, which equal the height of the cam rail, equal the lift of the carriers. Accordingly, a greater lift of the carriers require the cam rail to be higher. The higher rail requires a higher space for it, consequently raising the level of the carriers relative to the floor. As a result, this conveying apparatus is not suitable for a low floor structure.
The conveying apparatus disclosed in Publication No. H7-172538 includes a slat conveyor extending along a running track. This slat conveyor supports cross-linking mechanisms at intervals along it. Each of the cross-linking mechanisms supports a carrier and includes pairs of links, which are connected together by a fulcrum shaft. The slat conveyor is fitted with elevators, which can move vertically relative to it, and each of which supports one of the fulcrum shafts of the cross-linking mechanisms. A cam rail is fixed relative to the slat conveyor and lifts the elevators, which elevate the carriers. This conveying apparatus, as compared with the apparatus disclosed in Publication No. H7-157039, makes it possible to increase the lift of the carriers relative to the strokes of the elevators, which equal the height of the cam rail. Nevertheless, a greater lift of the carriers require the cam rail to be correspondingly higher. As a result, the conveying apparatus is still unsuitable for a low floor structure.